Trapdoor opener and closer



S. M. GRANGER. TRAPDO'OR OPENER AND fJLOSER.

APPLICATION FIL ED APR- 4| I921.

Patented Ndv. M, 1922.

CPtrmm- Patented Nov. 14, 1922.

'IT lAlliES mimrnoon ornnna Ann cnosna.

Application filed April 4, 1921. Serial No. 458,566.

To all whom it may concern Be it known that I, SAMUEL M. GRANGER, a citizen of the United States, residing at Kasota, in the county of Le Sueur and State of Minnesota, have invented a new and useful Trapdoor Opener and Closer, of which the following is a specification.

My invention relates to means for opening and closing trap doors, especially the kind of trap doors used for covering the grain dumping pits of grain elevators.

Said trap doors have always been objectionably heavy for the operator to open and close by hand all day long as often as a load of grain is'sold to the elevator and dumped into the receiving pit of same, but especially so of late years since auto trucks have got into use for hauling grain and these require the trap door to be much larger than those used at the time when only comparatively small wagons delivered the grain; and the main object of myinvention is to overcome such trouble and provide a trap door with means by which it may be easily opened and closed even though it may be of the largest type made. Another object is to enable the operator to open and close such door whether he is in his oflice or outside the of fice near the dumping pit.

In the accompanying drawing Fig. 1 is a partly sectional perspective view of a trap door and the platform in which it is located nearan office and a portion of the latter also shown.

Fig. 2 is a section on the line 2-2 in Fi 1.

Ileferring to the drawing by reference numerals 3 designates the platform covering a grain pit (not shown) near a grain elevator building (not shown) except that the wall 4 and floor 5 designate portions of the oflice occupied by the person weighing and receiving grain into the elevator.

The platform 3, of which 3 is the supporting joist or frame work, may also be considered as a part of the driveway over which the vehicles move and then after the door 6 is raised out of the opening 7 the grain is dumped throughthe latter into the p The door is hinged at 8 and provided at its underside with a guide 9 for an arm 10, which is fixed at 11 on a rock shaft 12. Said rock shaft is journaled in or to the frame work 3* and fixed on it are two radial arms 13, 14 and a hand lever 15.

The arm 13 (best shown in Fig. 2) has a lateral rib 16 near which is pivoted at 17 an arm extension 18 having a weight 19 pivotally suspended from its outer end. The arm 14, when the door is open, supports the bifurcated bottom end 20 of a short vertically reciprocable rod 21 which has a head 21*, and which is guided in a short sleeve or hollow post 22 secured upon the ofiice floor 5. Attached to the end of arm 14 is a cable or other flexible element 23, guided by a pulley 24 and having its upper end passed over a guide pullev 25 and provided with a I weight 26 having a handle"27.

In the operation of the device, when the door 6 is to be opened the operator, if he is outside the ofiice, takes hold of the lever 15 and swings it in the direction the door is to open. This is comparatively easy since the two weights 19 and 26 aid him in turning the shaft 12 and cause arm 10 to open the door; when the door has passed a vertical position and leans slightly backward it can go no further because either the arm 10 con tacts with the door at the point 28, or the arm 14 is up under the platform or has moved rod 21 upward to its limit. Weight 19 is now inactive because its rod or hanger 18 is not in contact with the rib or lug 16. To close the door the operator simply pushes the door forward over vertical position to permit it to close by gravity, it being a few pounds heavier than the two weights 19 and '26 combined.

If the operator is in the office he opens the door 6 by pulling downward at the handle 27, and closes the door by stepping on the head 21 of rod 21, so that the latter pushes on arm 14 sufliciently to swing the door forward past the vertical position so it can close by its own weight.

In any case where the party to use the device so prefers I dispense with either the weight 19 and its arms 18 and 13, and even the lever 15, or with the weight 26, chain 23, arm 14 and pedal 21-22, and where I thus may dispense with one weight I make the other sufiiciently heavy to leave the operator only a very few pounds to overcome in raising the door to open position. It is obvious that whichever weight is dispensed with the other one may be operated either within or outside the oflice.

It is also evident that the rock shaft 12 may be rocked or oscillated by gears and other means equivalent to those I have illusthe door and slidably embracing the second arm, a link pivotally suspended from the third arm and having a weight at its lower end, said third arm having a lateral projeotion arranged to engage the link and hold it aligned as an extension of the arm when the latter is swung toward a horizontal position by Closing of the door.

In testimony whereof I affix my signature. v

SAMUEL M. GRANGER. 

